Lesson 7- A&P

Question 1

The heart is located in the mediastinum, which is where?

Answer 1

The cavity between the lungs

Question 2

What is the heart composed of?

Answer 2

muscle fibers and nerves

Question 3

The heart is surrounded by the pericardium, which is what?

Answer 3

a sac characterized by two layers- the outer fibrous pericardium and the inner serous pericardium

Question 4

The outer fibrous pericardium does what?

Answer 4

anchors the heart to the surrounding structures

Question 5

inner serous pericardium consists of what?

Answer 5

consists of an outer parietal layer and an inner visceral layer

Question 6

where and what is pericardial fluid?

Answer 6

A thick layer of serous fluid, located between the parietal and inner visceral layers to provide a slippery surface for the movements of the heart

Question 7

The wall of the heart consists of what three layers?

Answer 7

epicardium, myocardium, endocardium

Question 8

(the outer layer of the walls of the heart) The visceral layer of the serous pericardium

Answer 8

epicardium

Question 9

muscular part of the heart that consists of contracting cardiac muscle and non contracting Pukinje fibers that conduct nerve impulses

Answer 9

myocardium

Question 10

thin, smooth, endothelial, inner layer of the heart-continuous with the inner lining of the blood vessels

Answer 10

endocardium

Question 11

The heart consists of these 4 chambers

Answer 11

right atrium, right ventricle, left atrium, left ventricle

Question 12

acts as a temporary storage chamber so that blood will be readily available for the right ventricle.

Answer 12

right atrium

Question 13

pumping chamber for the pulmonary circulation

Answer 13

Right ventricle

Question 14

receives oxygenated blood from the lungs, and like the right atrium, is a holding chamber for blood in readiness for it’s flow into the left ventricle.

Answer 14

left atrium

Question 15

pumping chamber for systemic circulation

Answer 15

left ventricle

Question 16

Action potentials (electrical impulses) in the heart originate in specialized cardiac muscle cells called ?

Answer 16

autorhythmic cells

Question 17

What are autorhythmic cells?

Answer 17

self excitable, able to generate an action potential without an external stimulation by nerve cells.

Question 18

These cells serve as a pacemaker to initiate the cardiac cycle and provide a conduction system to coordinate the contraction of muscle cells

Answer 18

autorhythmic cells

Question 19

Blood enters the heart from two vessels known as

Answer 19

superior and inferior vena cava

Question 20

All vessels bringing blood to the heart are called

Answer 20

veins

Question 21

All vessels carrying blood away from the heart are called

Answer 21

arteries

Question 22

Blood from the vena cavas empties into

Answer 22

the right atrium

Question 23

In the top right corner of the right atrium is a nerve bundle known as the

Answer 23

sino-atrial node, (SA NODE)

Question 24

This nerve bundle normally paces the heartbeat

Answer 24

SA node

Question 25

At the bottom left of the right atrium is another nerve bundle known as

Answer 25

atrioventricular node (AV node)

Question 26

This receives and transmits the paced signals generated by the SA node

Answer 26

AV node

Question 27

A slight delay of the electrical transmission of AV node and SA node occurs allowing for what

Answer 27

the atria to fully contract before the action potential is passed on.

Question 28

The AV bundle (bundle of His) receives the action potential from the AV node and transmits the impulse to the ventricles by the way of the what

Answer 28

right and left bundle branches

Question 29

Except for the AV bundle, which provides the only electrical connection, the atria are

Answer 29

electrically insulated from the ventricles.

Question 30

When the electrical signal generated by the SA node arrives at the AV node, it is delayed for approximately 0.1 second, and then rapidly conducted along the left and right bundle branches to a nerve network called the

Answer 30

Purkinje fibers (large-diameter fibers that conduct the action potential).

Question 31

Once blood has passed through the lungs (to engage in gas exchange), it returns to the heart through the

Answer 31

pulmonary veins.

Question 32

The pulmonary veins empty into the

Answer 32

left atrium

Question 33

As the left atrium contracts, the blood is forced through the

Answer 33

bicuspid valve into the left ventricle.

Question 34

The pulmonary veins empty into the

Answer 34

left atrium

Question 35

As the left atrium contracts, the blood is forced through

Answer 35

the bicuspid valve into the left ventricle.

Question 36

The left ventricle subsequently contracts (from the signal traveling through the left bundle branch), forcing the blood through the

Answer 36

aortic valve into the aorta, which is the largest artery in the body.

Question 37

The aorta then disseminates the blood throughout

Answer 37

the body

Question 38

all blood that travels through the right side of the heart is .

Answer 38

deoxygenated

Question 39

all blood that travels through the left side of the heart is

Answer 39

oxygenated

Question 40

Electrical currents generated by the heart during the cardiac cycle can be detected on the surface of the body by the

Answer 40

electrodes of an electrocardiograph.

Question 41

A recording of these currents, called an electrocardiogram (ECG or EKG), represents a sum of all the concurrent action potentials produced by the heart as detected by

Answer 41

the 12 electrodes of the electrocardiograph.

Question 42

In polysomnography, a what electrode EKG is typical for diagnostic testing?

Answer 42

3 electrode

Question 43

A single cardiac cycle produces a distinctive wave pattern, where peaks and valleys are indicated by

Answer 43

the letters PQRST

Question 44

The what wave is a small wave that represents the depolarization of the atria. During this wave, the muscles of the atria are contracting.

Answer 44

P wave

Question 45

The QRS complex is a rapid

Answer 45

down-up-down movement

Question 46

The QRS complex represents

Answer 46

depolarization of the ventricles.

Question 47

The upward movement produces a tall peak, indicated by

Answer 47

R

Question 48

The T wave represents the

Answer 48

repolarization of the ventricles

Question 49

Electrical activity generated by the repolarization of the atria is concealed by

Answer 49

the QRS complex.

Question 50

The SA node normally "fires" between

Answer 50

60-100 times each minute

Question 51

As the signal crosses the cardiac tissues, it can be recorded by

Answer 51

the EKG